I adopted a 2-year-old shepherd mix from the shelter a few months ago. He's a great dog and very smart, and has never made a mess in the house. When I came home from work today, my neighbor said he's barking at her every time she walks by with her dogs. I know what she means because he does that sometimes when I'm home, too. I don't want my neighbors complaining or calling animal control about the noise. How can I make him stop doing this?

Even if your neighbor wasn't complaining, it's best to nip this behavior in the bud. It can lead to other issues. Dogs that bark in windows also often start barking and even lunging on leash walks. We think it's a combination of boredom and frustration.

Make sure you are giving your dog plenty of exercise and mental stimulation on a daily basis. If you're not already doing so, take your dog for a walk each morning before you leave for work. Give him a Kong or Nylabone to chew on while you're at work. Leave the television or radio on a relaxing station to drown out the street noise. 

I'm a big believer in setting a dog up for success by not giving him the opportunity to fail. You can do this by crating him. The purpose of the crate is to create a safe, cozy environment where the dog can relax while you're at work. If for whatever reason you can't use a crate and the dog is house-trained, baby gates are a good alternative. Set it up in the kitchen or a spare room away from the front door. For some dogs a simple visual barrier is enough to deter the barking, so close the blinds or install vinyl film that obscures his vision but still lets light in.

This week's expert is Pauline Houliaras, certified professional trainer and behavior consultant and president of B-More Dog. Send your questions to sun.unleashed@gmail.com.